Value of 18F-FDG PET/CT in the diagnosis of multiple primary malignant neoplasms

Abstract

Objective To explore the value of 18F-FDG PET/CT in diagnosis of multiple primary malignant neoplasms.Methods Five thousand eight hundred and twenty-two patients with suspected tumors were retrospectively reviewed.All cases underwent 18F-FDG PET/CT and 32 patients were confirmed with multiple primary malignancies by biopsy or resection.Mean standardized uptake value (SUVmean) was calculated and SUV ≥ 2.5 and abnormal morphological changes on CT were used as a standard to diagnose a malignant tumor.The sensitivity and accuracy of PET/CT in diagnosis of multiple primary maligant neoplasms were calculated.Results The incidence rate of multiple primary malignant neoplasms was 0.55％.Double primary malignant neoplasms were in 30 cases and triplicate primary malignant tumors were in 2 cases.There were 66 malignant tumor lesions.The average of SUVmean in 66 malignant tumor lesions was 6.68±3.61.The results of PET/CT were 58 true positive lesions and 8 false negative lesions.The sensitivity and accuracy of 18F-FDG PET/CT in diagnosis of multiple primary malignant neoplasms were 87.9％ and 87.9％ respectively.Conclusion 18F-FDG PET/CT whole body scan has an important value in the diagnosis of multiple primary malignant neoplasms. Key words: Neoplasms;  Positron-emission tomography;  Tomography, X-ray computed;  Flurodeoxy-glucose F18